Yifei Teng / MPU6050

MPU6050 FreeIMU library

Dependents:   FreeIMU FreeIMU_external_magnetometer

Fork of MPU6050_tmp by Aloïs Wolff

Async MPU6050 library

My port of the MPU6050 library samples the chip at 500Hz using Timer. Async I2C is achieved using a custom I2C library, which supports I2C calls from interrupts. Link given below:

Import libraryMODI2C

Improvements to Olieman's MODI2C library. Supports calls from IRQ.

Last commit 28 Mar 2018 by Yifei Teng

Difference between this port and the Arduino MPU6050 library

The getMotion6 function only returns a copy of the last obtained readings, which is sampled at a frequency of 500Hz (adjustable). Hence it can be called at any frequency without taxing the I2C.

Diff: MPU6050.cpp

Revision:
9:d879deb55ae1
Parent:
7:95e74f827c08
Child:
11:9549be34fa7f
--- a/MPU6050.cpp	Tue Nov 05 11:28:54 2013 +0000
+++ b/MPU6050.cpp	Sat Nov 09 08:51:07 2013 +0000
@@ -40,7 +40,9 @@
 ===============================================
 */
 
+#include "MODI2C.h"
 #include "MPU6050.h"
+#include "rtos.h"
 
 //#define useDebugSerial
 
@@ -54,12 +56,8 @@
  */
 MPU6050::MPU6050() : debugSerial(USBTX, USBRX)
 {
-    devAddr = MPU6050_DEFAULT_ADDRESS;
-}
-
-MPU6050::MPU6050(I2C i2c) : debugSerial(USBTX, USBRX), i2Cdev(i2c)
-{
-    devAddr = MPU6050_DEFAULT_ADDRESS;
+    devAddr = MPU6050_DEFAULT_ADDRESS << 1;
+    debugSerial.baud(115200);
 }
 
 /** Specific address constructor.
@@ -70,7 +68,8 @@
  */
 MPU6050::MPU6050(uint8_t address) : debugSerial(USBTX, USBRX)
 {
-    devAddr = address;
+    devAddr = address << 1;
+    debugSerial.baud(115200);
 }
 
 /** Power on and prepare for general usage.
@@ -82,9 +81,7 @@
  */
 void MPU6050::initialize()
 {
-
 #ifdef useDebugSerial
-    debugSerial.baud(921600); //uses max serial speed
     debugSerial.printf("MPU6050::initialize start\n");
 #endif
     setClockSource(MPU6050_CLOCK_PLL_XGYRO);
@@ -1890,6 +1887,7 @@
     getMotion6(ax, ay, az, gx, gy, gz);
     // TODO: magnetometer integration
 }
+
 /** Get raw 6-axis motion sensor readings (accel/gyro).
  * Retrieves all currently available motion sensor values.
  * @param ax 16-bit signed integer container for accelerometer X-axis value
@@ -1904,14 +1902,34 @@
  */
 void MPU6050::getMotion6(int16_t* ax, int16_t* ay, int16_t* az, int16_t* gx, int16_t* gy, int16_t* gz)
 {
-    i2Cdev.readBytes(devAddr, MPU6050_RA_ACCEL_XOUT_H, 14, buffer);
-    *ax = (((int16_t)buffer[0]) << 8) | buffer[1];
-    *ay = (((int16_t)buffer[2]) << 8) | buffer[3];
-    *az = (((int16_t)buffer[4]) << 8) | buffer[5];
-    *gx = (((int16_t)buffer[8]) << 8) | buffer[9];
-    *gy = (((int16_t)buffer[10]) << 8) | buffer[11];
-    *gz = (((int16_t)buffer[12]) << 8) | buffer[13];
+    *ax = ax_cache;
+    *ay = ay_cache;
+    *az = az_cache;
+    *gx = gx_cache;
+    *gy = gy_cache;
+    *gz = gz_cache;
 }
+
+uint32_t mpureadfin(uint32_t param){
+    MPU6050* ins = (MPU6050*)param;
+    ins->ax_cache = (((int16_t)ins->mpu_buffer[0]) << 8) | ins->mpu_buffer[1];
+    ins->ay_cache = (((int16_t)ins->mpu_buffer[2]) << 8) | ins->mpu_buffer[3];
+    ins->az_cache = (((int16_t)ins->mpu_buffer[4]) << 8) | ins->mpu_buffer[5];
+    ins->gx_cache = (((int16_t)ins->mpu_buffer[8]) << 8) | ins->mpu_buffer[9];
+    ins->gy_cache = (((int16_t)ins->mpu_buffer[10]) << 8) | ins->mpu_buffer[11];
+    ins->gz_cache = (((int16_t)ins->mpu_buffer[12]) << 8) | ins->mpu_buffer[13];
+    return 0;
+}
+
+void MPU6050::mpu_sample_func(){
+    i2Cdev.readBytes_nb(devAddr, &mpu_cmd, 14, (uint8_t*)mpu_buffer, &mpureadfin, this);
+}
+
+void MPU6050::start_sampling(){
+    mpu_cmd = MPU6050_RA_ACCEL_XOUT_H;
+    mpu_sampling.attach_us(this, &MPU6050::mpu_sample_func, 2000);
+}
+
 /** Get 3-axis accelerometer readings.
  * These registers store the most recent accelerometer measurements.
  * Accelerometer measurements are written to these registers at the Sample Rate